Reporting power headroom information

ABSTRACT

Apparatuses, methods, and systems are disclosed for reporting power headroom (“PH”) information. One apparatus is configured with a first serving cell for PUSCH transmissions having a first SCS and a second serving cell for PUSCH transmissions having a second SCS larger than the first SCS. The apparatus has an uplink resource allocation for a first slot on the first serving cell, where the first slot overlaps in time with multiple second slots on the second serving cell, and has an uplink resource allocation for at least one of the multiple second slots that are overlapped by the first slot. A processor calculates PH information for the second serving cell for a first PUSCH scheduled on a first one of the multiple second slots and a transceiver transmits the PH information in an uplink transmission on the first slot.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending U.S. patent applicationSer. No. 16/271,685 entitled “REPORTING POWER HEADROOM INFORMATION” andfiled on Feb. 8, 2019 for Joachim Loehr, Alexander Johann MariaGolitschek Edler von Elbwart, Hossein Bagheri, Prateek Basu Mallick,Ravi Kuchibhotla, and Vijay Nangia, which is incorporated herein byreference. U.S. application Ser. No. 16/271,685 claims priority to U.S.Provisional Patent Application No. 62/628,241 entitled “PHR PROCEDUREWHEN AGGREGATING CARRIERS CONFIGURED WITH DIFFERENT TTI LENGTHS” andfiled on Feb. 8, 2018 for Joachim Loehr, Alexander Johann MariaGolitschek Edler von Elbwart, Hossein Bagheri, Prateek Basu Mallick,Ravi Kuchibhotla, and Vijay Nangia, which is incorporated herein byreference.

FIELD

The subject matter disclosed herein relates generally to wirelesscommunications and more particularly relates to reporting power headroominformation.

BACKGROUND

The following abbreviations are herewith defined, at least some of whichare referred to within the following description: Third GenerationPartnership Project (“3GPP”), Fifth-Generation Core (“5GC”), Access andMobility Management Function (“AMF”), Access Point Name (“APN”), AccessStratum (“AS”), Adjacent Channel Leakage Ratio (“ACLR”), BandwidthAdaptation (“BA”), Bandwidth Part (“BWP”), Beam Failure Detection(“BFD”), Beam Failure Recovery Request (“BFRR”), Binary Phase ShiftKeying (“BPSK”), Buffer Status Report (“BSR”), Block Error Rate(“BLER”), Carrier Aggregation (“CA”), Cell-Specific Radio NetworkTemporary Identifier (“C-RNTI”), Clear Channel Assessment (“CCA”),Cyclic Prefix (“CP”), Common Search Space (“C-SS”), Control Element(“CE”), Cyclical Redundancy Check (“CRC”), Channel State Information(“CSI”), Common Search Space (“CSS”), Data Radio Bearer (“DRB,” e.g.,carrying user plane data), Demodulation Reference Signal (“DM-RS”),Discontinuous Reception (“DRX”), Discrete Fourier Transform Spread(“DFTS”), Downlink Control Information (“DCI”), Downlink (“DL”),Downlink Pilot Time Slot (“DwPTS”), Enhanced Clear Channel Assessment(“eCCA”), Enhanced Licensed Assisted Access (“eLAA”), Enhanced MobileBroadband (“eMBB”), Evolved Node B (“eNB”), Evolved Packet Core (“EPC”),Evolved UMTS Terrestrial Radio Access Network (“E-UTRAN”), Frame BasedEquipment (“FBE”), Frequency Division Duplex (“FDD”), Frequency DivisionMultiple Access (“FDMA”), Frequency Division Orthogonal Cover Code(“FD-OCC”), Guard Period (“GP”), General Packet Radio Service (“GPRS”),Global System for Mobile Communications (“GSM”), Hybrid Automatic RepeatRequest (“HARQ”), Internet-of-Things (“IoT”), Licensed Assisted Access(“LAA”), Load Based Equipment (“LBE”), Listen-Before-Talk (“LBT”),Logical Channel (“LCH”), Long Term Evolution (“LTE”), Master InformationBlock (“MIB”), Multiple Access (“MA”), Medium Access Control (“MAC”),Master Cell Group (“MCG”), Modulation Coding Scheme (“MC S”), MachineType Communication (“MTC”), Mobility management Entity (“MME”), MultipleInput Multiple Output (“MIMO”), Multi User Shared Access (“MUSA”),Narrowband (“NB”), Next Generation (e.g., 5G) Node-B (“gNB”), NextGeneration Radio Access Network (“NG-RAN”), New Radio (“NR”, e.g., 5Gradio access), New Data Indicator (“NDI”), Non-Orthogonal MultipleAccess (“NOMA”), Orthogonal Frequency Division Multiplexing (“OFDM”),Packet Data Convergence Protocol (“PDCP”), Primary Cell (“PCell”),Physical Broadcast Channel (“PBCH”), Packet Data Network (“PDN”),Protocol Data Unit (“PDU”), Physical Downlink Control Channel (“PDCCH”),Physical Downlink Shared Channel (“PDSCH”), Pattern Division MultipleAccess (“PDMA”), Physical Hybrid ARQ Indicator Channel (“PHICH”),Physical Random Access Channel (“PRACH”), Physical Resource Block(“PRB”), Physical Uplink Control Channel (“PUCCH”), Physical UplinkShared Channel (“PUSCH”), Quality of Service (“QoS”), Quadrature PhaseShift Keying (“QPSK”), Radio Link Control (“RLC”), Radio Link Failure(“RLF”), Radio Link Monitoring (“RLM”), Radio Resource Control (“RRC”),Random-Access Procedure (“RACH”), Random Access Response (“RAR”), RadioNetwork Temporary Identifier (“RNTI”), Reference Signal (“RS”),Reference Signal Received Power (“RSRP”), Remaining Minimum SystemInformation (“RMSI”), Resource Block Assignment (“RBA”), Resource SpreadMultiple Access (“RSMA”), Round Trip Time (“RTT”), Receive (“RX”),Sparse Code Multiple Access (“SCMA”), Scheduling Request (“SR”),Signaling Radio Bearer (“SRB,” e.g., carrying control plane data),Single Carrier Frequency Division Multiple Access (“SC-FDMA”), SecondaryCell (“SCell”), Secondary Cell Group (“SCG”), Shared Channel (“SCH”),Signal-to-Interference-Plus-Noise Ratio (“SINR”), Serving Gateway(“SGW”), Service Data Unit (“SDU”), Sequence Number (“SN”), SessionManagement Function (“SMF”), System Information (“SI”), SystemInformation Block (“SIB”), Synchronization Signal (“SS”), TransportBlock (“TB”), Transport Block Size (“TB S”), Time-Division Duplex(“TDD”), Time Division Multiplex (“TDM”), Time Division Orthogonal CoverCode (“TD-OCC”), Transmission Time Interval (“TTI”), Transmit (“TX”),Uplink Control Information (“UCI”), User Entity/Equipment (MobileTerminal) (“the UE”), Uplink (“UL”), User Plane (“UP”), Universal MobileTelecommunications System (“UMTS”), Uplink Pilot Time Slot (“UpPTS”),Ultra-reliability and Low-latency Communications (“URLLC”), WirelessLocal Area Network (“WLAN”), and Worldwide Interoperability forMicrowave Access (“WiMAX”). As used herein, “HARQ-ACK” may representcollectively the Positive Acknowledge (“ACK”) and the NegativeAcknowledge (“NACK”). ACK means that a TB is correctly received whileNACK (or NAK) means a TB is erroneously received.

In certain wireless communications networks, such as LTE, a UE reportsextended power headroom report (“PHR”) or carrier aggregation, i.e., itreports power headroom (“PH”) info for each activated serving celltogether with P_(CMAX), the total maximum UE transmit power. Because thesubframe/TTI length is in LTE same for all carriers the PHR reportingsubframes, the subframes to which the power headroom information refersare aligned. However, some wireless communication networks, such as the3GPP 5G NR, support carriers with different OFDM numerologies and/ordifferent TTIs.

BRIEF SUMMARY

Methods for reporting power headroom information are disclosed.Apparatuses and systems also perform the functions of the methods. Themethods may also be embodied in one or more computer program productscomprising executable code.

One method of a User Equipment (“UE”) for reporting power headroominformation includes being configured with a first serving cell forphysical uplink shared channel (“PUSCH”) transmissions having a firstsubcarrier spacing (“SCS”) and a second serving cell for PUSCHtransmissions having a second SCS, wherein the first SCS is smaller thanthe second SCS. The method includes having an uplink resource allocationfor a first slot on the first serving cell, wherein the first slotoverlaps in time with multiple second slots on the second serving cell,and having an uplink resource allocation for at least one of themultiple second slots on the second serving cell that are overlapped bythe first slot on the first serving cell. The method includescalculating power headroom (“PH”) information for the second servingcell for a first PUSCH scheduled on a first slot of the multiple secondslots that fully overlaps with the first slot on the first serving celland transmitting the PH information in an uplink transmission on thefirst slot on the first serving cell.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the embodiments briefly described abovewill be rendered by reference to specific embodiments that areillustrated in the appended drawings. Understanding that these drawingsdepict only some embodiments and are not therefore to be considered tobe limiting of scope, the embodiments will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings, in which:

FIG. 1 is a schematic block diagram illustrating one embodiment of awireless communication system for reporting power headroom information;

FIG. 2 is a block diagram illustrating one embodiment of a RAN forreporting power headroom information;

FIG. 3 is a block diagram illustrating another embodiment of a RAN forreporting power headroom information;

FIG. 4 is a schematic block diagram illustrating one embodiment of anapparatus that may be used for reporting power headroom information;

FIG. 5 is a block diagram illustrating a first embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 6 is a block diagram illustrating a second embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 7 is a block diagram illustrating a third embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 8 is a block diagram illustrating a fourth embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 9 is a block diagram illustrating a fifth embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 10 is a block diagram illustrating a sixth embodiment of a scenariowhere a UE aggregates carriers configured with different TDU lengths;

FIG. 11 is a flow chart diagram illustrating one method of reportingpower headroom information; and

FIG. 12 is a flow chart diagram illustrating another method of reportingpower headroom information.

DETAILED DESCRIPTION

As will be appreciated by one skilled in the art, aspects of theembodiments may be embodied as a system, apparatus, method, or programproduct. Accordingly, embodiments may take the form of an entirelyhardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Furthermore,embodiments may take the form of a program product embodied in one ormore computer readable storage devices storing machine readable code,computer readable code, and/or program code, referred hereafter as code.The storage devices may be tangible, non-transitory, and/ornon-transmission. The storage devices may not embody signals. In acertain embodiment, the storage devices only employ signals foraccessing code.

Any combination of one or more computer readable medium may be utilized.The computer readable medium may be a computer readable storage medium.The computer readable storage medium may be a storage device storing thecode. The storage device may be, for example, but not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, holographic,micromechanical, or semiconductor system, apparatus, or device, or anysuitable combination of the foregoing.

More specific examples (a non-exhaustive list) of the storage devicewould include the following: an electrical connection having one or morewires, a portable computer diskette, a hard disk, a random-access memory(“RAM”), a read-only memory (“ROM”), an erasable programmable read-onlymemory (“EPROM” or Flash memory), a portable compact disc read-onlymemory (“CD-ROM”), an optical storage device, a magnetic storage device,or any suitable combination of the foregoing. In the context of thisdocument, a computer readable storage medium may be any tangible mediumthat can contain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

Code for carrying out operations for embodiments may be any number oflines and may be written in any combination of one or more programminglanguages including an object-oriented programming language such asPython, Ruby, Java, Smalltalk, C++, or the like, and conventionalprocedural programming languages, such as the “C” programming language,or the like, and/or machine languages such as assembly languages. Thecode may execute entirely on the user's computer, partly on the user'scomputer, as a stand-alone software package, partly on the user'scomputer and partly on a remote computer or entirely on the remotecomputer or server. In the latter scenario, the remote computer may beconnected to the user's computer through any type of network, includinga local area network (“LAN”) or a wide area network (“WAN”), or theconnection may be made to an external computer (for example, through theInternet using an Internet Service Provider).

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, appearances of the phrases“in one embodiment,” “in an embodiment,” and similar language throughoutthis specification may, but do not necessarily, all refer to the sameembodiment, but mean “one or more but not all embodiments” unlessexpressly specified otherwise. The terms “including,” “comprising,”“having,” and variations thereof mean “including but not limited to,”unless expressly specified otherwise. An enumerated listing of itemsdoes not imply that any or all of the items are mutually exclusive,unless expressly specified otherwise. The terms “a,” “an,” and “the”also refer to “one or more” unless expressly specified otherwise.

Furthermore, the described features, structures, or characteristics ofthe embodiments may be combined in any suitable manner. In the followingdescription, numerous specific details are provided, such as examples ofprogramming, software modules, user selections, network transactions,database queries, database structures, hardware modules, hardwarecircuits, hardware chips, etc., to provide a thorough understanding ofembodiments. One skilled in the relevant art will recognize, however,that embodiments may be practiced without one or more of the specificdetails, or with other methods, components, materials, and so forth. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of anembodiment.

Aspects of the embodiments are described below with reference toschematic flowchart diagrams and/or schematic block diagrams of methods,apparatuses, systems, and program products according to embodiments. Itwill be understood that each block of the schematic flowchart diagramsand/or schematic block diagrams, and combinations of blocks in theschematic flowchart diagrams and/or schematic block diagrams, can beimplemented by code. The code may be provided to a processor of ageneral-purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions/acts specified in the schematic flowchartdiagrams and/or schematic block diagrams block or blocks.

The code may also be stored in a storage device that can direct acomputer, other programmable data processing apparatus, or other devicesto function in a particular manner, such that the instructions stored inthe storage device produce an article of manufacture includinginstructions which implement the function/act specified in the schematicflowchart diagrams and/or schematic block diagrams block or blocks.

The code may also be loaded onto a computer, other programmable dataprocessing apparatus, or other devices to cause a series of operationalsteps to be performed on the computer, other programmable apparatus, orother devices to produce a computer implemented process such that thecode which execute on the computer or other programmable apparatusprovide processes for implementing the functions/acts specified in theflowchart and/or block diagram block or blocks.

The schematic flowchart diagrams and/or schematic block diagrams in theFigures illustrate the architecture, functionality, and operation ofpossible implementations of apparatuses, systems, methods, and programproducts according to various embodiments. In this regard, each block inthe schematic flowchart diagrams and/or schematic block diagrams mayrepresent a module, segment, or portion of code, which includes one ormore executable instructions of the code for implementing the specifiedlogical function(s).

It should also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in theFigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. Other steps and methods may be conceived that are equivalentin function, logic, or effect to one or more blocks, or portionsthereof, of the illustrated Figures.

Although various arrow types and line types may be employed in theflowchart and/or block diagrams, they are understood not to limit thescope of the corresponding embodiments. Indeed, some arrows or otherconnectors may be used to indicate only the logical flow of the depictedembodiment. For instance, an arrow may indicate a waiting or monitoringperiod of unspecified duration between enumerated steps of the depictedembodiment. It will also be noted that each block of the block diagramsand/or flowchart diagrams, and combinations of blocks in the blockdiagrams and/or flowchart diagrams, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware and code.

The description of elements in each figure may refer to elements ofproceeding figures. Like numbers refer to like elements in all figures,including alternate embodiments of like elements.

Generally, the present disclosure describes systems, methods, andapparatus for reporting power headroom information when UE is configuredwith multiple uplink carriers, e.g. in a carrier aggregation deployment,respectively serving cells, for example by a UE communicating with aradio network using a first UL carrier and a second UL carrierconcurrently.

In various embodiments, the UE receives an UL resource allocation for afirst transmission duration unit on the first UL carrier. Here, thefirst transmission duration unit overlaps in time with at least twosecond transmission duration units on the second UL carrier. The UEidentifies a third transmission duration unit on the second UL carrier.Here, the third transmission duration unit comprises at least one of thesecond transmission duration units. The UE calculates power headroom(“PH”) information for the second UL carrier associated with the thirdtransmission duration unit and reports the PH information in an ULtransmission on the first transmission duration unit.

In some embodiments, each of the first and second UL carriers isassociated with a different serving cell. In some embodiments, the UEmay receive an UL resource allocation for at least one of theoverlapping second transmission duration units on the second UL carrier.

In some embodiments, the first transmission duration unit corresponds toa slot on the first UL carrier and the second transmission duration unitcorresponds to a slot on the second UL carrier. For example, the baseunit may be a gNB in a 5G RAN, where the first UL carrier is configuredwith a first subcarrier spacing (“SCS”) and the second UL carrier isconfigured with a second SCS, the first SCS being smaller than thesecond SCS. Accordingly, the first UL carrier will have slots withlonger time-duration than the second UL carrier, such that multiplesecond slots on the second UL carrier fully overlap with the first slot.

In such embodiments, the UE calculates PH information for a firstphysical UL shared channel (“PUSCH”) scheduled on the first of themultiple second slots that fully overlaps with the first slot on thefirst UL carrier. Here, reporting PH information for the second ULcarrier in an UL transmission on the first slot may include the UEtransmitting on a PUSCH a power headroom report (“PHR”) that containsthe PH information for the first PUSCH. In certain embodiments,

In some embodiments, the first transmission duration unit corresponds toa transmit time interval (“TTI”) of the first UL carrier and the secondtransmission duration unit corresponds to a TTI of the second ULcarrier. In certain embodiments, the first UL carrier is configured witha first TTI length and the second UL carrier is configured with a secondTTI length, wherein the first TTI length is larger than the second TTIlength. For example, the base unit may be an LTE eNB, wherein the secondTTI length corresponds to a shortened TTI (“sTTI”) length. Moreover, thefirst TTI length may also correspond to a sTTI.

In such embodiments, calculating PH information for the second ULcarrier associated with the third transmission duration unit comprisesthe UE calculating PH for a TTI duration longer than the second TTIlength. In certain embodiments, the length of the third transmissionduration unit (e.g., third TTI) is greater than the length of the firstTTI. In certain embodiments, the third transmission duration unit (e.g.,third TTI) is equal to a subframe. In certain embodiments, calculatingPH information for the second UL carrier associated with the thirdtransmission duration unit comprises calculating PH information for asubframe containing the first TTI. In certain embodiments, the thirdtransmission duration unit contains multiple TTIs of the second ULcarrier (e.g., the third TTI overlaps multiple sTTIs on the second ULcarrier).

In some embodiments, the UE calculates the PH information according to apredefined reference format. In certain embodiments, the processorcalculates the PH information assuming the apparatus is not scheduled totransmit a PUSCH in the third transmission duration unit.

In various embodiments, the reported PH information comprises a powerheadroom level computed based on the UL resource allocation. In someembodiments, TTIs of the second UL carrier are configured with a smallerTTI length than TTIs of the first UL carrier, wherein the at least onesecond TTI on the second UL carrier has a shortened TTI length that isless than 1 millisecond. In some embodiments, the PH information iscalculated based on an uplink resource allocation received for the thirdtransmission duration unit. In such embodiments, the uplink transmissionon the third transmission duration may be either stopped or dropped.

FIG. 1 depicts a wireless communication system 100 for receiving systeminformation at a UE, according to embodiments of the disclosure. In oneembodiment, the wireless communication system 100 includes at least oneremote unit 105, a radio access network (“RAN”) 120, and a mobile corenetwork 140. The RAN 120 and the mobile core network 140 form a mobilecommunication network. The RAN 120 may be composed of a base unit 110with which the remote unit 105 communicates using wireless communicationlinks 115. Even though a specific number of remote units 105, base units110, wireless communication links 115, RANs 120, and mobile corenetworks 140 are depicted in FIG. 1 , one of skill in the art willrecognize that any number of remote units 105, base units 110, wirelesscommunication links 115, RANs 120, and mobile core networks 140 may beincluded in the wireless communication system 100.

In one implementation, the wireless communication system 100 iscompliant with the 5G system specified in the 3GPP specifications. Moregenerally, however, the wireless communication system 100 may implementsome other open or proprietary communication network, for example, LTEor WiMAX, among other networks. The present disclosure is not intendedto be limited to the implementation of any particular wirelesscommunication system architecture or protocol.

In one embodiment, the remote units 105 may include computing devices,such as desktop computers, laptop computers, personal digital assistants(“PDAs”), tablet computers, smart phones, smart televisions (e.g.,televisions connected to the Internet), smart appliances (e.g.,appliances connected to the Internet), set-top boxes, game consoles,security systems (including security cameras), vehicle on-boardcomputers, network devices (e.g., routers, switches, modems), or thelike. In some embodiments, the remote units 105 include wearabledevices, such as smart watches, fitness bands, optical head-mounteddisplays, or the like. Moreover, the remote units 105 may be referred toas the UEs, subscriber units, mobiles, mobile stations, users,terminals, mobile terminals, fixed terminals, subscriber stations, userterminals, wireless transmit/receive unit (“WTRU”), a device, or byother terminology used in the art.

The remote units 105 may communicate directly with one or more of thebase units 110 in the RAN 120 via uplink (“UL”) and downlink (“DL”)communication signals. Furthermore, the UL and DL communication signalsmay be carried over the wireless communication links 115. Here, the RAN120 is an intermediate network that provides the remote units 105 withaccess to the mobile core network 140.

In some embodiments, the remote units 105 communicate with anapplication server 151 via a network connection with the mobile corenetwork 140. For example, an application 107 (e.g., web browser, mediaclient, telephone/VoIP application) in a remote unit 105 may trigger theremote unit 105 to establish a PDU session (or other data connection)with the mobile core network 140 via the RAN 120. The mobile corenetwork 140 then relays traffic between the remote unit 105 and theapplication server 151 in the packet data network 150 using the PDUsession. Note that the remote unit 105 may establish one or more PDUsessions (or other data connections) with the mobile core network 140.As such, the remote unit 105 may concurrently have at least one PDUsession for communicating with the packet data network 150 and at leastone PDU session for communicating with another data network (not shown).

The base units 110 may be distributed over a geographic region. Incertain embodiments, a base unit 110 may also be referred to as anaccess terminal, an access point, a base, a base station, a Node-B, aneNB, a gNB, a Home Node-B, a relay node, or by any other terminologyused in the art. The base units 110 are generally part of a radio accessnetwork (“RAN”), such as the RAN 120, that may include one or morecontrollers communicably coupled to one or more corresponding base units110. These and other elements of radio access network are notillustrated but are well known generally by those having ordinary skillin the art. The base units 110 connect to the mobile core network 140via the RAN 120.

The base units 110 may serve a number of remote units 105 within aserving area, for example, a cell or a cell sector, via a wirelesscommunication link 115. The base units 110 may communicate directly withone or more of the remote units 105 via communication signals.Generally, the base units 110 transmit DL communication signals to servethe remote units 105 in the time, frequency, and/or spatial domain.Furthermore, the DL communication signals may be carried over thewireless communication links 115. The wireless communication links 115may be any suitable carrier in licensed or unlicensed radio spectrum.The wireless communication links 115 facilitate communication betweenone or more of the remote units 105 and/or one or more of the base units110.

In one embodiment, the mobile core network 140 is a 5G core (“5GC”) orthe evolved packet core (“EPC”), which may be coupled to a packet datanetwork 150, like the Internet and private data networks, among otherdata networks. A remote unit 105 may have a subscription or otheraccount with the mobile core network 140. Each mobile core network 140belongs to a single public land mobile network (“PLMN”). The presentdisclosure is not intended to be limited to the implementation of anyparticular wireless communication system architecture or protocol.

The mobile core network 140 includes several network functions (“NFs”).As depicted, the mobile core network 140 includes multiple user planefunctions (“UPFs”) 145. The mobile core network 140 also includesmultiple control plane functions including, but not limited to, anAccess and Mobility Management Function (“AMF”) 141 that serves the RAN120, a Session Management Function (“SMF”) 143, and a Policy ControlFunction (“PCF”) 147. In certain embodiments, the mobile core network140 may also include an Authentication Server Function (“AUSF”), aUnified Data Management function (“UDM”) 149, a Network RepositoryFunction (“NRF”) (used by the various NFs to discover and communicatewith each other over APIs), or other NFs defined for the 5GC.

Although specific numbers and types of network functions are depicted inFIG. 1 , one of skill in the art will recognize that any number and typeof network functions may be included in the mobile core network 140.Moreover, where the mobile core network 140 is an EPC, the depictednetwork functions may be replaced with appropriate EPC entities, such asan MME, S-GW, P-GW, HSS, and the like. In certain embodiments, themobile core network 140 may include a AAA server.

In various embodiments, the mobile core network 140 supports differenttypes of mobile data connections and different types of network slices,wherein each mobile data connection utilizes a specific network slice.Here, a “network slice” refers to a portion of the mobile core network140 optimized for a certain traffic type or communication service. Incertain embodiments, the various network slices may include separateinstances of network functions, such as the SMF 143 and UPF 145. In someembodiments, the different network slices may share some common networkfunctions, such as the AMF 141. The different network slices are notshown in FIG. 1 for ease of illustration, but their support is assumed.

While FIG. 1 depicts components of a 5G RAN and a 5G core network, thedescribed embodiments for PHR reporting 125 in a wideband carrier applyto other types of communication networks, including IEEE 802.11variants, UMTS, LTE variants, CDMA 2000, Bluetooth, and the like. Forexample, in an LTE/EPC variant, the AMF 141 may be mapped to an MME, theSMF 143 may be mapped to a control plane portion of a PGW, the UPF 145may be mapped to a STW and a user plane portion of the PGW, etc.

To assist the base unit 110 to schedule uplink transmission resources todifferent remote units 105 in an appropriate way, each remote unit 105reports its available power headroom (“PH”) to the base unit 110, e.g.,using a power headroom report (“PHR”) 125. Using a received PHR, thebase unit 110 may determine how much more uplink bandwidth per sub-framea remote unit 105 is capable of using, i.e. how close to itstransmission power limits the remote unit 105 is operating. The PHindicates the difference between the maximum UE uplink transmit powerand the estimated power for UL-SCH transmission. In various embodiments,the remote unit 105 power headroom (PH) in dB valid for sub-frame “i” isdefined by:PH(i)=P _(CMAX)−{10 log₁₀(M _(PUSCH)(i))+P _(0_PUSCH)(j)+α(j)·PL+Δ_(TF)(i)+f(i)}   Equation 1

Here, P_(CMAX) is the total maximum UE transmit power and is a valuechosen by the user equipment in the given range of P_(CMAX_L) andP_(CMAX_H) based on the following constraints:P _(CMAX_L) ≤P _(CMAX) ≤P _(CMAX_H)  Equation 2P _(CMAX_L)=min(P _(EMAX) −ΔT _(C) ,P _(PowerClass) −MPR−AMPR−ΔT_(C))  Equation 3P _(CMAX_H)=min(P _(EMAX) ,P _(PowerClass))  Equation 4

Here, P_(EMAX) is a value signaled by the network. The MPR is a powerreduction value used to control the adjacent channel leakage power ratio(ACLR) associated with the various modulation schemes and thetransmission bandwidth. AMPR is the additional maximum power reduction.It is a band specific value and applied by the UE when configured by thenetwork. One example of values for ΔT_(C), MPR and AMPR may be found in3GPP TS36.101.

In various embodiments, the remote unit 105 sends the PHR 125 as a MACControl Element (“MAC CE”). The base unit 110 may configure parametersto control various triggers for reporting power headroom depending onthe system load and the requirements of its scheduling algorithm.

In various embodiments, the range of the power headroom report is from+40 to −23 dB. Note that negative part of the range enables the remoteunit 105 to signal to the base unit 110 the extent to which it hasreceived an UL grant which would require more transmission power thanthe remote unit 105 has available. The base unit 110 may then reduce theamount of uplink resources in a subsequent grant (dynamic orsemi-static), thus freeing up transmission resources which could be thenallocated to other remote units.

In various embodiments, the power headroom report 125, e.g., PHR MAC CE,may only be sent in a sub-frame for which the remote unit 105 has avalid uplink resource, i.e., a PUSCH resource. In general, the PHR 125relates to the sub-frame in which it is sent and is therefore anestimation or prediction rather than a direct measurement (because theremote unit 105 cannot directly measure its actual transmission powerheadroom for the subframe in which the report is to be transmitted).

In various embodiments, the remote unit 105 is configured for carrieraggregation, wherein the remote unit 105 used at least a first carrierand a second carrier concurrently. Each component carrier (e.g., thefirst and second carriers) may be associated with a different servingcell. Where the remote unit 105 is configured with multiple concurrentserving cells, the power headroom defined in Equation 1 is calculatedand reported for each serving cell/component carrier. For the case ofcarrier aggregation, the remote unit 105 must consider both the totalmaximum UE transmit power P_(CMAX) and a component carrier-specificmaximum transmit power P_(CMAX,c).

Because simultaneous PUSCH-PUCCH transmission is supported in carrieraggregation, two different types of PH types are supported for CA. PHtype 1 indicates the difference between P_(CMAX,c) and estimated PUSCHpower, while PH type 2 indicates the difference between P_(CMAX,c) andestimated power of PUSCH and PUCCH combined. Note that PH type 2 is onlyapplicable for PCell, whereas PH type 1 is applicable for both PCell andSCell. Because it is beneficial for the base unit 110 to always know thepower situation for all activated uplink carrier/serving carrier forfuture uplink scheduling, the remote unit 105 may transmit an extendedPH MAC CE on one of the serving cells (PCell and SCells) which has avalid uplink resource for PUSCH. The extended PH MAC CE includes powerheadroom information (Type1/Type2) for each activated uplink componentcarrier.

While the following solutions are discussed in the context of carrieraggregation, the principles described herein are also applicable to Dualconnectivity (DC) which allows a remote unit 105 to receive datasimultaneously from different base units 110 in order to boost theperformance in a heterogeneous network with dedicated carrierdeployment. In Dual Connectivity when a PHR has been triggered, the UEsends power headroom information for all activated cells (includingserving cells of both cell groups) to the eNB. When UE reports PH infoof secondary cell group (“SCG”) cells to the main base unit 110 (e.g.,MeNB) or PH info of main cell group (“MCG”) cells to the secondary baseunit 110 (e.g., SeNB), Type2 PH information for the PUCCH cell (PUCCHfor the SCG) is included. Power headroom info for the serving cells inthe other CG may be calculated based on some reference format (e.g.,virtual PHR) or based on actual PUSCH/PUCCH transmissions.

In various embodiments, the remote unit 105 may be configured with aShort Processing Time (SPT) and a shorter TTI length. Short TransmissionTime Interval (Short TTI) provides support for TTI length shorter than 1ms DL-SCH and UL-SCH. To support the short TTI, the associated controlchannels, shortened PDCCH (“sPDCCH,” containing downlink controlinformation (DCI) for short TTI operation, referred to as “sDCI”) andshortened PUCCH (“sPUCCH”) are also transmitted with duration shorterthan 1 ms. Over the physical layer, DL and UL transmissions use eitherslots or subslots when short TTI is configured. Recall that in LTE thereare 2 slots of 7 OFDM/SC-FDMA symbol duration in a subframe. As usedherein, a “subslot” refers to a transmission duration unit of either 2OFDM/SC-FDMA symbol or 3 OFDM/SC-FDMA symbol duration. As such, three“subslots” fit within a slot. To support the short TTI, the remote unit105 transmits (sub)slot-based PUSCH (also referred to as shortened PUSCHor “sPUSCH”).

In various embodiments, the RAN 120 may support different OFDMnumerologies, i.e. sub-carrier spacing (SCS), CP length, in a singleframework, e.g., to support use cases/deployment scenarios with diverserequirements in terms of data rates, latency, and coverage. For example,eMBB is to support peak data rates (e.g., 20 Gbps for downlink and 10Gbps for uplink) while URLLC is to support ultra-low latency (0.5 ms forUL and DL each for user plane latency) and high reliability (1-10-5within 1 ms). Therefore, the OFDM numerology that is suitable for oneuse case might not work well for another. Note that different OFDMnumerologies have different subcarrier spacings, affecting OFDM symbolduration, cyclic prefix (CP) duration, and number of symbols perscheduling interval. Different numerologies may occur across differentcarrier(s) for a given UE as well as different numerologies within thesame carrier for a given UE, i.e. different OFDM numerologies aremultiplexed in frequency-domain and/or time-domain within the samecarrier or across different carriers.

When carrier aggregation is combined with different numerologies for NRor, for LTE, with shortened TTI, one transmission duration unit (“TDU”,e.g., NR slot or LTE TTI) of a carrier can overlap (coincide) withmultiple TDUs of another carrier. In this case the base unit 110, maynot be aware which TDU the power headroom information refers to. Forexample, in a scenario where an extended PHR report is triggered andsubsequently transmitted in a slot/TTI, which overlaps with multipleslots/TTIs on a different carrier, the base unit 110 does not know whichof the overlapped slot/TTI from the multiple slots/TTIs is the referencefor the PH calculation. Without knowledge of the reference TDU, the baseunit 110 may establish its future scheduling decisions on wrongassumptions, i.e. how close the UE is operating on the power limit,which may lead to either power scaling or under-utilization ofresources. Note that data transmissions may be scheduled to span one ormultiple UL TDUs (e.g., slots/TTIs). Similarly, multiple datatransmissions (e.g., PUSCH transmissions) also may be scheduled withinone slot, which is also referred to as e.g. sub-slot as outlined below.

In various embodiments, the remote unit 105 is configured with differentUL TDU lengths for different serving cells, e.g. for a carrieraggregation. With possible simultaneous UL transmissions using differentPUSCH durations across serving cells, a base unit 110, e.g., gNB or eNB,needs to know which TDU a power headroom calculation is based on, sothat it correctly interprets a received PHR and to enable the base unit110 to schedule subsequent transmissions (e.g., sTTI/TTI/slot) properly.As discussed above, the PHR provides the base unit 110 with informationon path loss, TPC status and the used MPR for the corresponding uplinktransmission.

In certain embodiments, the remote unit 105 may receive indications fromthe base unit 110 of sets of frequency domain resource blocks forpossible PUSCH data transmission in uplink of a first TDU length on afirst component carrier and a second TDU length on the second componentcarrier. In one embodiment, the remote unit 105, having been allocatedresources for PUSCH on the first carrier, then identifies a TDU on thesecond carrier computes a PHR for the second carrier based on theidentified TDU. In certain embodiments, the remote unit 105 may derive(and indicate to the base unit 110) a reference TDU index (e.g., slotindex or TTI index) associated with the PHR for the second carrier. Theremote unit 105 transmits the PHR for the second carrier to the baseunit 110.

FIG. 2 depicts an access network 200 for reporting power headroominformation, according to embodiments of the disclosure. The accessnetwork 200 include a UE 205 that uses two UL carriers concurrently, afirst component carrier (“CC1”) 220 and a second component carrier(“CC2”). In various embodiments, each component carrier is associatedwith a different serving cell. In the depicted embodiment, the firstcarrier 220 and the second component carrier 230 are associated with thesame RAN node (“gNB-1”) 210, e.g., a Carrier Aggregation scenario. Here,the RAN node 210 may be gNB in a 5G-RAN.

The first component carrier 220 has transmission duration units oflonger length than the second component carrier 230. In variousembodiments, these transmission duration units correspond to slots in NRwith the first component carrier being configured with a smallersubcarrier spacing (“SCS”) than the second component carrier. As such,multiple slots on the second component carrier 230 fit within a singleslot on the first component carrier 220. In the depicted embodiment, oneslot of the first component carrier 220 overlaps with two slots of thesecond component carrier 230.

As depicted, the first component carrier 220 includes a first slot 221(denoted “slot-0”), a second slot 222 (denoted “slot-1”), a third slot223 (denoted “slot-2”), and a fourth slot 224 (denoted “slot-3”). At thesame time, the second component carrier 230 includes a first slot 231(denoted “slot-0”), a second slot 232 (denoted “slot-1”), a third slot233 (denoted “slot-2”), a fourth slot 234 (denoted “slot-3”), a fifthslot 235 (denoted “slot-4”), a sixth slot 236 (denoted “slot-5”), aseventh slot 237 (denoted “slot-6”), and an eighth slot 238 (denoted“slot-7”). While the depicted embodiment shows alignment of the slotboundaries, in other embodiments the slot boundaries of the firstcomponent carrier 220 do not coincide with slot boundaries of the secondcomponent carrier 230.

In the access network 200, the UE 205 is allocated uplink resources inthe slot 223, denoted “slot-2”, on the first component carrier 220.Here, the allocated resources may correspond to an active bandwidth parton the first component carrier 220. Note that the slot 223 overlaps withthe slots 235 and 236 on the second component carrier 230. Here, the UE205 provides a type1 PHR for slot 223 of the first carrier 220 in aPUSCH transmission on slot 223. Moreover, the UE 205 provides a PHR forthe first PUSCH, if any, on the first of the multiple slots on thesecond carrier 230 (e.g., on an active bandwidth part of the secondcarrier 230) that fully overlaps with the slot 223. Here, the slot 235is the first slot on the second carrier to fully overlap with the slot223. Thus, the UE 205 calculates a PHR (e.g., a type1 PHR) for the slot235 and sends it to the network in the PUSCH transmission on slot 223(e.g., sends the PHR 240 over the first carrier 220).

In certain embodiments, the slot 235 and slot 236 are scheduled foruplink transmission (e.g., PUSCH). Here, the uplink grants for theseslots may include dynamic grants and/or configured (e.g.,semi-persistent) grants. In one embodiment, the slots 235 and 236 may bescheduled individually. In another embodiment, the slots 235 and 236 arescheduled via a multi-slot grant. In certain embodiments, the UE 205computes an “actual” PHR for the second component carrier. As usedherein, “actual” PH refers to a power headroom level calculates based onactual transmissions. In contrast, “virtual” PH refers to a powerheadroom level calculated based on a predefined reference format.

FIG. 3 depicts an access network 300 for reporting power headroominformation, according to embodiments of the disclosure. The accessnetwork 300 includes the UE 205 that uses two UL carriers concurrently,a first component carrier (“CC1”) 320 and a second component carrier(“CC2”). In the depicted embodiment, the first carrier 320 and thesecond component carrier 330 are associated with a first RAN node(“eNB-1”) 310. Here, the RAN node 310 may be eNB in a LTE-RAN.

The first component carrier 320 has transmission duration units oflonger length than the second component carrier 330. In variousembodiments, these transmission duration units correspond to TTIs, forexample short TTIs (sTTIs) in LTE as depicted, with the first componentcarrier being configured with a longer TTI length than the secondcomponent carrier. As such, multiple sTTIs on the second componentcarrier 330 fit within a single sTTI on the first component carrier 320.In the depicted embodiment, one sTTI of the first component carrier 320overlaps with three sTTIs of the second component carrier 330. Here, thefirst component carrier is configured with a slot-length TTI (e.g., 7OFDM symbols in duration) and the second component carrier 330 isconfigured with subslot-length TTI (e.g., 2 or 3 OFDM symbols induration; here in a “2-2-3” pattern, such that every three sTTIs add upto 7 OFDM symbols).

As depicted, the first component carrier 320 includes a first sTTI 321(denoted “sTTI-1”), a second sTTI 322 (denoted “sTTI-2”), a third sTTI323 (denoted “sTTI-3”), and a fourth sTTI 324 (denoted “sTTI-4”). At thesame time, the second component carrier 330 includes a first sTTI 331(denoted “sTTI-1”), a second sTTI 332 (denoted “sTTI-2”), a third sTTI333 (denoted “sTTI-3”), a fourth sTTI 334 (denoted “sTTI-4”), a fifthsTTI 335 (denoted “sTTI-5”), a sixth sTTI 336 (denoted “sTTI-6”), aseventh sTTI 337 (denoted “sTTI-7”), an eighth sTTI 338 (denoted“sTTI-8”), a ninth sTTI 339 (denoted “sTTI-9”), a tenth sTTI 340(denoted “sTTI-10”), an eleventh sTTI 341 (denoted “sTTI-11”), and atwelfth sTTI 342 (denoted “sTTI-12”). While the depicted embodimentshows alignment of the sTTI boundaries, in other embodiments the sTTIboundaries of the first component carrier 320 do not coincide with sTTIboundaries of the second component carrier 330.

In the access network 300, the UE 205 is allocated uplink resources inthe sTTI 323, denoted “sTTI-3”, on the first component carrier 320. Notethat the sTTI 323 overlaps with the sTTIs 337, 338 and 339 on the secondcomponent carrier 330. Here, the UE 205 provides a PHR for sTTI 323 ofthe first carrier 320 in a PUSCH transmission on sTTI 323. Moreover, theUE 205 provides a PHR 350 for time duration unit on the second carrier330 that is larger than the sTTI length(s) of the second carrier 330. Inthe depicted embodiment, the UE 205 calculates a PHR for asubframe-length TDU on the second carrier 330. Here, the UE 205 computesthe Power headroom for the subframe 345 on the second carrier containingthe sTTI 323 with the PUSCH allocation on the first carrier. In otherembodiments, the UE 205 calculates a PHR for a slot-length TDU on thesecond carrier, denoted as “TTI-3” 347.

In certain embodiments, the sTTIs 337-339 are scheduled for uplinktransmission (e.g., PUSCH). Here, the uplink grants for these sTTIs mayinclude dynamic grants and/or configured (e.g., semi-persistent) grants.In one embodiment, the sTTIs 337-339 may be scheduled individually. Inanother embodiment, the sTTIs 337-339 are scheduled via a multi-sTTIgrant. In certain embodiments, the UE 205 computes an “virtual” PHR forthe second component carrier. As used herein, “virtual” PH refers to apower headroom level calculated based on a predefined reference format.In other embodiments, the UE 205 may compute an “actual” PHR for thesecond component carrier.

FIG. 4 depicts a user equipment apparatus 400 that may be used forreporting power headroom information, according to embodiments of thedisclosure. The user equipment apparatus 400 may be one embodiment ofthe remote unit 105 and/or the UE 205, described above. Furthermore, theuser equipment apparatus 400 may include a processor 405, a memory 410,an input device 415, an output device 420, a transceiver 425 forcommunicating with one or more base units 110.

As depicted, the transceiver 425 may include a transmitter 430 and areceiver 435. The transceiver 425 may also support one or more networkinterfaces 440, such as the Uu interface used to communicate with a gNB,or other suitable interface for communicating with the RAN 120. In someembodiments, the input device 415 and the output device 420 are combinedinto a single device, such as a touchscreen. In certain embodiments, theuser equipment apparatus 400 may not include any input device 415 and/oroutput device 420.

In various embodiments, the processor 405 receives (i.e., via thetransceiver 425) a service configuration for a first serving cell forPUSCH transmissions having a first SCS and a second serving cell forPUSCH transmissions having a second SCS, where the first SCS is smallerthan the second SCS. The processor 405 receives (i.e., via thetransceiver 425) an uplink resource allocation for a first slot on thefirst serving cell, where the first slot overlaps in time with multiplesecond slots on the second serving cell. Additionally, the processorreceives (i.e., via the transceiver 425) an uplink resource allocationfor at least one of the multiple second slots on the second serving cellthat are overlapped by the first slot on the first serving cell. Theprocessor 405 calculates power headroom (“PH”) information for thesecond serving cell for a first PUSCH scheduled on a first slot of themultiple second slots that fully overlaps with the first slot on thefirst serving cell and controls the transceiver 425 to transmit the PHinformation in an uplink transmission on the first slot on the firstserving cell.

In some embodiments, the processor 405 further receives (via thetransceiver 425) a second uplink resource allocation for at least one ofthe overlapping second slots on the second uplink carrier. In someembodiments, transmitting the PH information in an uplink transmissionon the first slot on the first serving cell includes transmitting on aPUSCH a PHR that contains the PH information for the first PUSCHscheduled on the first of the multiple second slots that is fullyoverlapped by the first slot.

In some embodiments, transmitting the PH information includestransmitting a Type 1 power headroom report. In some embodiments,transmitting the PH information includes transmitting a PHR MAC CE inthe uplink transmission in an allocated uplink allocation on the firstserving cell.

In some embodiments, the first slot corresponds to a TTI of the firstserving cell and the second slots correspond to TTIs of the secondserving cell. In certain embodiments, the PH information for the secondserving cell is calculated for TTI duration that contains multiple TTIsof the second serving cell.

In some embodiments, the first serving cell is configured with a firstTTI length and the second serving cell is configured with a second TTIlength, where the first TTI length is larger than the second TTI length.In certain embodiments, calculating PH information for the secondserving cell includes calculating PH information for a subframe thatuses the first TTI length.

In certain embodiments, calculating PH information for the secondserving cell includes calculating PH for a TTI duration longer than thesecond TTI length. In one embodiment, the PH for the second serving cellis calculated for TTI duration that is greater than the length of thefirst TTI. In another embodiment, the PH for the second serving cell iscalculated for TTI duration that is equal to a subframe.

In some embodiments, the PH information is calculated according to apredefined reference format. In certain embodiments, the PH informationis calculated assuming the UE is not scheduled to transmit a PUSCH inthe at least two second slots that fully overlaps with the first slot.

In some embodiments, the at least one of the second slots on the secondserving cell has a shortened TTI length that is less than 1 millisecond.In some embodiments, the reported PH information includes a powerheadroom level computed based on the uplink resource allocation.

In some embodiments, the PH information is calculated based on an uplinkresource allocation received for a transmission duration correspondingto the multiple second slots on the second serving cell that areoverlapped by the first slot on the first serving cell. In certainembodiments, an uplink transmission on the transmission duration is oneof: stopped and dropped.

In various embodiments, the transceiver 425 communicates with a baseunit using a first uplink carrier and a second uplink carrierconcurrently. Here, each carrier has a different transmission durationunit length, wherein the first uplink carrier has a longer transmissionduration unit length than the second uplink carrier. At some point intime, the processor 405 receives an uplink resource allocation for afirst transmission duration unit on the first uplink carrier anddetermines a third transmission duration unit on the second uplinkcarrier. Here, the first transmission duration unit overlaps in timewith at least two second transmission duration units on the seconduplink carrier and the third transmission duration unit comprises atleast one of the second transmission duration units. The processor 405calculates power headroom (“PH”) information for the second uplinkcarrier associated with the third transmission duration unit andreports, via the transceiver 425, the PH information in an uplinktransmission on the first transmission duration unit.

In some embodiments, each of the first and second uplink carriers isassociated with a different serving cell. In some embodiments, theprocessor further receives an uplink resource allocation for at leastone of the overlapping second transmission duration units on the seconduplink carrier.

In some embodiments, the first transmission duration unit corresponds toa slot on the first uplink carrier and the second transmission durationunit corresponds to a slot on the second uplink carrier. In certainembodiments, multiple second slots on the second uplink carrier fullyoverlap with the first slot. In such embodiments, the processor 405calculates PH information for a first physical uplink shared channel(“PUSCH”) scheduled on the first of the multiple second slots that fullyoverlaps with the first slot on the first uplink carrier, whereinreporting PH information for the second uplink carrier in an uplinktransmission on the first slot comprises transmitting on a PUSCH a powerheadroom report (“PHR”) that contains the PH information for the firstPUSCH. In certain embodiments, the first uplink carrier is configuredwith a first subcarrier spacing (“SCS”) and the second uplink carrier isconfigured with a second SCS, wherein the first SCS is smaller than thesecond SCS.

In some embodiments, the first transmission duration unit corresponds toa transmit time interval (“TTI”) of the first uplink carrier and thesecond transmission duration unit corresponds to a TTI of the seconduplink carrier. In certain embodiments, the first uplink carrier isconfigured with a first TTI length and the second uplink carrier isconfigured with a second TTI length, wherein the first TTI length islarger than the second TTI length. In such embodiments, calculating PHinformation for the second uplink carrier associated with the thirdtransmission duration unit comprises calculating PH for a TTI durationlonger than the second TTI length.

In certain embodiments, the length of the third transmission durationunit is greater than the length of the first TTI. In certainembodiments, the third transmission duration unit is equal to asubframe. In certain embodiments, calculating PH information for thesecond uplink carrier associated with the third transmission durationunit comprises calculating PH information for a subframe containing thefirst TTI. In certain embodiments, the third transmission duration unitcontains multiple TTIs of the second uplink carrier.

In some embodiments, the processor 420 calculates the PH informationaccording to a predefined reference format. In certain embodiments, theprocessor 420 calculates the PH information assuming the apparatus isnot scheduled to transmit a PUSCH in the third transmission durationunit.

In various embodiments, the reported PH information comprises a powerheadroom level computed based on the uplink resource allocation. In someembodiments, the at least one of the second transmission duration unitson the second uplink carrier (e.g., second TTI on the second uplinkcarrier) has a shortened TTI length that is less than 1 millisecond. Insome embodiments, the PH information is calculated based on an uplinkresource allocation received for the third transmission duration unit.In such embodiments, the uplink transmission on the third transmissionduration may be either stopped or dropped.

In some embodiments, the transceiver 425 receives a first indication(e.g., first UL resource grant) from a mobile communication network(e.g., from the base unit 110) indicating a first set of frequencydomain resource blocks for possible PUSCH data transmission and at leastone uplink transmission duration unit (“TDU”) of a first TDU length on afirst component carrier. The transceiver 425 may also receive a secondindication (e.g., second UL resource grant) from the mobilecommunication network indicating a second set of frequency domainresource blocks for possible PUSCH data transmission and at least oneuplink TDU of a second TDU length on the second component carrier. Here,the first component carrier and the second component carrier areconfigured with different TDU lengths (e.g., different TTI/sTTI lengthsin an LTE deployment or different slot lengths in an NR deployment).

The processor 405 computes a first PHR based on at least one of:transmissions of the first TDU length only being present in a first TDUon the first carrier, and a reference format. In certain embodiments,the processor 405 may also select at least one second TDU of the secondTDU length on the second component carrier and compute a second PHRbased on at least one of: transmissions of the second TDU length onlybeing present in the selected second TDU on the second componentcarrier, and a reference format. Moreover, the processor 405 may derivea reference TDU index associated with the second PHR.

The processor 405 controls the transceiver 425 to transmit at least thefirst PHR and the second PHR to the base unit (e.g., gNB or eNB). Here,the second TDU length is shorter than the first TDU length, such thatthe first TDU encompasses one or more TDUs of the second TDU length. Forexample, an integer number of TDUs of the second TTI length may fitwithin the time duration of the first TDU.

In one embodiment, the second indication is an RRC configurationassigning the second set of frequency domain resource blocks forpossible PUSCH data transmissions (e.g., a configured UL grant, such assemi-persistent scheduling). Additionally, the RRC configuration mayfurther indicate at least one of the modulation encoding scheme (“MCS”)and a transport block size (“TBS”) index. In such embodiments, thesecond PHR may contain a power headroom value computed based ontransmissions of the second TTI length only being present in the secondTTI on the second component carrier.

Additionally, in the above embodiments computing the second PHR may bebased on the allocation of the second set of frequency domain resourceblocks, irrespective of the presence of transmissions in the second TTIon the second component carrier (e.g., the processor 405 calculates thesecond PHR assuming that PUSCH transmissions will occur on the one ormore second TDUs, even if PUSCH is actually not transmitted on the oneor more second TDUs). In such embodiments, a configured maximum transmitpower value (e.g., P_(CMAX,c)) may be included in the second PHR.

In certain embodiments, the first PHR and at least the second PHR aretransmitted via a single PHR MAC control element. In certainembodiments, the reference TDU index is derived based on at least thesecond TDU index within the first TDU.

In some embodiments, the processor 405 selects a second TDU from a setof TDUs of the second TDU length within the first TDU. Here, theprocessor 405 may select the earliest scheduled TDU of the second TDUlength within the first TDU for uplink transmission. In anotherembodiment, the processor 405 may select the second TDU from the set ofTDUs of the second TDU length within the first TDU based on thescheduled TDU of the second TDU length within the first TDU for uplinktransmission having a smallest power headroom field value among thescheduled TDU of the second TDU length within the first TDU for uplinktransmission. In a third embodiment, the second TDU selected from a setof TDUs of the second TDU length within the first TDU based on theearliest scheduled TDU of the second TDU length within the first TDU foruplink transmission if no PHR is due on any earlier TTI of the secondTTI length within the first TDU, and otherwise based on the earliest TDUof the second TDU length within the first TDU for which a PHR is due.

In some embodiments, computing the second PHR is based on the referenceformat (e.g., a virtual PHR). In such embodiments, the second PHR may becomputed according to a third TTI with a third TTI length. In one suchembodiment, the third TTI length is equal to one subframe (e.g., 1 ms).In an alternate embodiment, the third TTI length is the same as thefirst TTI length. Also, in such embodiments, uplink transmissions of thethird TTI length may not be configured for the second component carrier.Moreover, in these embodiments the transmit power control command valuemay be a fixed value. Further, the second PHR calculation may beassociated with fixed resource block allocation and a transmit powercontrol command value the fixed value of the transmit power controlcommand may be selected based on the third TTI length. In certainembodiments, the first component carrier belongs to the first PUCCHgroup and the second component carrier belongs to a second PUCCH group.

The memory 410, in one embodiment, is a computer readable storagemedium. In some embodiments, the memory 410 includes volatile computerstorage media. For example, the memory 410 may include a RAM, includingdynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or staticRAM (“SRAM”). In some embodiments, the memory 410 includes non-volatilecomputer storage media. For example, the memory 410 may include a harddisk drive, a flash memory, or any other suitable non-volatile computerstorage device. In some embodiments, the memory 410 includes bothvolatile and non-volatile computer storage media.

In some embodiments, the memory 410 stores data related to reportingpower headroom information. For example, the memory 410 may store one ormore power headroom reports, e.g., of the first and second typesdescribed herein. Additionally, the memory 410 may store data forreporting power headroom information, such as PH values, resourceallocations, TTI index, and the like. In certain embodiments, the memory410 also stores program code and related data, such as an operatingsystem or other controller algorithms operating on the remote unit 105.

The input device 415, in one embodiment, may include any known computerinput device including a touch panel, a button, a keyboard, a stylus, amicrophone, or the like. In some embodiments, the input device 415 maybe integrated with the output device 420, for example, as a touchscreenor similar touch-sensitive display. In some embodiments, the inputdevice 415 includes a touchscreen such that text may be input using avirtual keyboard displayed on the touchscreen and/or by handwriting onthe touchscreen. In some embodiments, the input device 415 includes twoor more different devices, such as a keyboard and a touch panel.

The output device 420, in one embodiment, is designed to output visual,audible, and/or haptic signals. In some embodiments, the output device420 includes an electronically controllable display or display devicecapable of outputting visual data to a user. For example, the outputdevice 420 may include, but is not limited to, an LCD display, an LEDdisplay, an OLED display, a projector, or similar display device capableof outputting images, text, or the like to a user. As another,non-limiting, example, the output device 420 may include a wearabledisplay separate from, but communicatively coupled to, the rest of theuser equipment apparatus 400, such as a smart watch, smart glasses, aheads-up display, or the like. Further, the output device 420 may be acomponent of a smart phone, a personal digital assistant, a television,a table computer, a notebook (laptop) computer, a personal computer, avehicle dashboard, or the like.

In certain embodiments, the output device 420 includes one or morespeakers for producing sound. For example, the output device 420 mayproduce an audible alert or notification (e.g., a beep or chime). Insome embodiments, the output device 420 includes one or more hapticdevices for producing vibrations, motion, or other haptic feedback. Insome embodiments, all or portions of the output device 420 may beintegrated with the input device 415. For example, the input device 415and output device 420 may form a touchscreen or similar touch-sensitivedisplay. In other embodiments, the output device 420 may be located nearthe input device 415.

As discussed above, the transceiver 425 communicates with one or morenetwork functions of a mobile communication network via one or moreaccess networks. The transceiver 425 operates under the control of theprocessor 405 to transmit messages, data, and other signals and also toreceive messages, data, and other signals. For example, the processor405 may selectively activate the transceiver 425 (or portions thereof)at particular times in order to send and receive messages.

In various embodiments, the transceiver 425 includes at least onetransmitter 430 and at least one receiver 435. One or more transmitters430 may be used to provide UL communication signals to a base unit 110,such as the PUSCH transmissions containing MR described herein.Similarly, one or more receivers 435 may be used to receive DLcommunication signals from the base unit 110, as described herein.Although only one transmitter 430 and one receiver 435 are illustrated,the user equipment apparatus 400 may have any suitable number oftransmitters 430 and receivers 435. Further, the transmitter(s) 425 andthe receiver(s) 430 may be any suitable type of transmitters andreceivers. In one embodiment, the transceiver 425 includes a firsttransmitter/receiver pair used to communicate with a mobilecommunication network over licensed radio spectrum and a secondtransmitter/receiver pair used to communicate with a mobilecommunication network over unlicensed radio spectrum.

In certain embodiments, the first transmitter/receiver pair used tocommunicate with a mobile communication network over licensed radiospectrum and the second transmitter/receiver pair used to communicatewith a mobile communication network over unlicensed radio spectrum maybe combined into a single transceiver unit, for example a single chipperforming functions for use with both licensed and unlicensed radiospectrum. In some embodiments, the first transmitter/receiver pair andthe second transmitter/receiver pair may share one or more hardwarecomponents. For example, certain transceivers 425, transmitters 430, andreceivers 435 may be implemented as physically separate components thataccess a shared hardware resource and/or software resource, such as forexample, the network interface 440.

In various embodiments, one or more transmitters 430 and/or one or morereceivers 435 may be implemented and/or integrated into a singlehardware component, such as a multi-transceiver chip, asystem-on-a-chip, an application specific integrated circuit (“ASIC”),or other type of hardware component. In certain embodiments, one or moretransmitters 430 and/or one or more receivers 435 may be implementedand/or integrated into a multi-chip module. In some embodiments, othercomponents such as the network interface 440 or other hardwarecomponents/circuits may be integrated with any number of transmitters430 and/or receivers 435 into a single chip. In such embodiment, thetransmitters 430 and receivers 435 may be logically configured as atransceiver 425 that uses one more common control signals or as modulartransmitters 430 and receivers 435 implemented in the same hardware chipor in a multi-chip module.

FIG. 5 depicts a first scenario 500 where the UE 205 aggregates servingcells (e.g., in a carrier aggregation deployment) with different TDUlengths, according to various embodiments of the disclosure. Here, theUE aggregates a first component carrier (e.g., “CC1”) 505 and secondcomponent carrier (e.g., “CC2”) 510. In certain embodiments, both CC1505 and CC2 510 are LTE carriers configured with a short TTI ofdifferent lengths, i.e. both TTI lengths are shorter than 1 ms. Asdepicted, one TTI of CC1 505 overlaps with 3 TTIs of CC2 510. As anexample, one TTI on CC1 505 may correspond to an LTE slot (7 OFDM Symbol(“OS”)), whereas an UL transmission on CC2 510 uses sub-slots (e.g.,either two OFDM/SC-FDMA symbols or three OFDM/SC-FDMA symbols induration). In other embodiments, the CC1 505 and CC2 510 are NR carriersconfigured with different OFDM numerologies, such that multiple NR slotson CC2 510 overlap with one NR slot on CC1 505.

In the first scenario 500, an uplink transmission on (s)PUSCH isscheduled for sTTI-1 on CC1 505. Here, the UE 205 multiplexes a PHR MACCE in the sPUSCH in sTTI-1 on CC1 505. The UE 205 is further scheduledwith an uplink transmission on (s)PUSCH in sTTI-2 on CC2 510.

According to one embodiment, the UE 205 reports Power headroominformation for sTTI-2 on CC2 510 within the PHR MAC CE transmitted insTTI-1 on CC1 505. Reporting the power headroom information for sTTI-2on CC2 has the advantage that the UE 205 reports an actual PHR, i.e.,PHR is reported for a scheduled TTI. The actual PHR provides informationon the used MPR for the corresponding uplink transmission to the RANnode. Therefore, for cases when the UE 205 is scheduled for an uplinktransmission in one of the overlapped TTIs, the UE 205 may report theactual PH for this scheduled TTI.

FIG. 6 depicts a second scenario 600 where the UE 205 aggregates servingcells (e.g., in a carrier aggregation deployment) with different TTIlengths, according to various embodiments of the disclosure. Here, theUE 205 aggregates a first component carrier (e.g., “CC1”) 605 and secondcomponent carrier (e.g., “CC2”) 610. In certain embodiments, both CC1505 and CC2 510 are LTE carriers configured with a short TTI ofdifferent lengths, such that one TTI on CC1 may correspond to an LTEslot, and three TTIs on CC2 fit within one TTI on CC1. In otherembodiments, the CC1 605 and CC2 610 are NR carriers configured withdifferent OFDM numerologies, such that multiple NR slots on CC2 610overlap with one NR slot on CC1 605.

Note that in the second scenario 600, the UE is scheduled for sPUSCH onsTTI-1 of CC1 605 as well as sTTI-1 of CC2 610. In the second scenario600, the UE 205 reports PH information for sTTI-1 of CC2 within the PHRMAC CE transmitted on CC1. In certain embodiments, when the UE 205 isscheduled for an uplink transmission in one of the overlapped TTIs, theUE 205 reports the power headroom information for this scheduled TTI,unless there is another sTTI having its PHR due before the PHR MAC CE isgenerated. Thus, in the first scenario 500 shown in FIG. 5 (e.g., sPUSCHat sTTI-2 of CC2 is scheduled with n+8 timing, i.e., 8 subslots beforesTTI-2), the UE 205 may report PH information for sTTI-2 of CC2 withinthe PHR MAC CE transmitted on CC1 when no PHR is due in sTTI-1 of CC2(e.g., due to expiration of periodicPHR-Timer). However, if there is aPHR due in sTTI-1 of CC2 then the UE 205 may instead report PHinformation for sTTI-1 of CC2 within the PHR MAC CE transmitted on CC1and not that of sTTI-2 of CC2.

FIG. 7 depicts a third scenario 700 where a UE aggregates serving cells(e.g., in a carrier aggregation deployment) with different TTI lengths,according to various embodiments of the disclosure. Here, the UEaggregates a first component carrier (e.g., “CC1”) 705 and secondcomponent carrier (e.g., “CC2”) 710. Note that in the third scenario700, the UE is scheduled for sPUSCH on sTTI-1 of CC1 705 and also onsTTI-1, sTTI-2, and sTTI-3 of CC2 710.

For cases when there is only one of the overlapping TDUs on CC2 which isscheduled for an uplink transmission, the RAN node is aware for whichTDU the UE 205 has reported power headroom information. However, in caseseveral of the overlapping TDUs on CC2 are scheduled for an uplinktransmission, then the RAN node and UE 205 need a common understandingfor which of the overlapping TDUs the UE 205 is to report power headroominformation. According to one embodiment, the UE 205 reports powerheadroom information for the first of the overlapping TDUs which arescheduled for an uplink transmission. One example of reporting for thefirst overlapping TDU is described above with reference to FIG. 2 .

Given the third scenario 700, where all three overlapping (s)TTIs arescheduled for an uplink transmission, e.g., sPUSCH is scheduled insTTI-1 through sTTI-3 on CC2 (e.g., via individual UL grants or viamulti-TTI UL grant), the UE 205 may report power headroom informationfor sTTI-1 of CC2 710 within the PHR MAC CE transmission on CC1 705. Inan alternative embodiment the UE 205 reports power headroom informationfor the last scheduled overlapping sTTI (e.g., sTTI-3). However sincethe UL grant timing, i.e. timing between UL grant and correspondinguplink transmission, needs to be also considered, reporting powerheadroom for the first overlapped TTI may ensure sufficient processingtime to calculate the PH information.

FIG. 8 depicts a fourth scenario 800 where the UE 205 aggregates servingcells (e.g., in a carrier aggregation deployment) with different TTIlengths, according to various embodiments of the disclosure. In variousembodiments, when PHR is due on more than one CC, the UE 205 may reportthe PH information for the earliest PHR occasion, and the pending PHRcorresponding to the longer TTI may be cancelled if a virtual PHR isreported for the CC associated with the longer TTI assuming a shorterTTI length. Here, the UE aggregates a first component carrier (e.g.,“CC1”) 805 and second component carrier (e.g., “CC2”) 810. Note that inthe fourth scenario 800, the UE is scheduled for sPUSCH on sTTI-1 of CC1805. During the depicted time duration, CC2 810 includes a TTI (e.g.,subframe)-based PUSCH.

In the fourth scenario 800, assume sPUSCH at sTTI-1 of CC1 805 isscheduled with n+4 timing, i.e., 4 slots before sTTI-1, andsubframe-based PUSCH is scheduled with n+3 timing, i.e., 3 subframesbefore the subframe where PUSCH is transmitted). Here, the UE 205 mayreport a (e.g., virtual) PHR computed assuming the PHR calculation forthe UL sTTI in which the PHR is transmitted (according to 3GPPagreement), and may further cancel the PHR that was due onsubframe-length TTI on CC2 810.

FIG. 9 depicts a fifth scenario 900 where the UE 205 aggregates servingcells (e.g., in a carrier aggregation deployment) with different TTIlengths, according to various embodiments of the disclosure. Apart fromthe shorter TTI durations introduced for LTE Rel-15 or NR, also theminimum timing from UL grant transmission to UL PUSCH transmission hasbeen reduced. Therefore, the different timing relations, i.e., (s)PDCCHto sPUSCH, also need to be considered when reporting power headroominformation.

In the fifth scenario 900, the UE 205 aggregates a first componentcarrier (e.g., “CC1”) 905 and second component carrier (e.g., “CC2”)910. Note that in the fifth scenario 900, the UE is scheduled for sPUSCHon sTTI-4 of CC1 905 and on sTTI-14 of CC2 910. As depicted, the UE 205is aggregating two serving cells/CCs with different TTI lengths, whereone TTI of CC1 overlaps with three TTIs of CC2 910. Also, the timingrelations between UL grant and the corresponding UL PUSCH transmissionmay be different for the two aggregated serving cells.

As power headroom is calculated based on a received UL grant, i.e.estimated UL power according to the grant, when configured withdifferent serving cells having different TTI lengths (and potentiallyalso different timing relations, i.e. from UL grant to corresponding ULtransmission), when generating the PHR MAC CE the UE 205 may not beaware (e.g., at sTTI-0 of CC1 905) whether there will be some uplinktransmission on the other carriers in any of the TTIs which overlap withthe TTI in which PHR MAC CE is transmitted. For example, the UE mightnot be fast enough to process the UL grant(s) for the overlapping TTIson the other carriers when calculating the power headroom information.Taking the exemplary scenario depicted in FIG. 9 , when generating thePHR MAC CE for transmission on CC1 905 in sTTI-4, the UE is not aware ofthe presence of an UL grant for the overlapping sTTI(s) on CC2 910, i.e.sTTI-13, sTTI-14 and sTTI-15.

Therefore, the UE 205 may determine whether the power headroom value foran activated Serving Cell is based on real transmission or a referenceformat by considering the downlink control information which has beenreceived until and including the PDCCH occasion in which the first ULgrant is received since a PHR has been triggered. Here, the UE 205considers all the UL grants having received until it receives an ULgrant allocating UL resource for inclusion of PHR MAC CE. In the exampleabove, the UE 205 considers all UL allocations having been receiveduntil and including sTTI-0 on CC1 for determining the PHR format.Therefore, the UE 205 reports a virtual PHR for CC2 since no UL grantinformation is available for the overlapping sTTIs on CC2, i.e.,sTTI-13, sTTI-14 and sTTI-15. Because the UE 205 doesn't have UL grantinformation for any of the overlapping sTTIs on CC2, the UE 205 wouldreport always a virtual PHR for CC2 regardless of how the reference PHRTTI is defined, i.e. TTI to which a reported PHR refers to.

However, considering that the UE 205 might be also configured with ULresources without dynamic scheduling, i.e., Semi-Persistent scheduling(SPS) or configured grants, it is still required to define a referencePHR TTI.

Assuming that the UE 205 is allocated configured grants for one ormultiple of the overlapping sTTIs on CC2, the UE 205 needs to know forwhich of the overlapping TTI to report power headroom information. Itshould be noted that the UE 205 may be aware of these configured grantsat sTTI-0 on CC1 and hence should consider them for PHR reporting. Here,the reference PHR TTI could be e.g. defined—as outlined in the otherembodiment—as the first of the overlapping (s)TTIs which are scheduledfor an uplink transmission. Alternatively, the reference PHR TTI, i.e.TTI for which Power headroom level is computed, could be defined as thefirst overlapped (s)TTI.

According to another embodiment, the UE 205 reports a virtual PHR for acarrier/serving cell which has a different TTI length than the servingcell on which PHR MAC CE is transmitted. Taken the examples depicted inthe above figures, the PHR MAC CE is transmitted on CC1 which has a TTIlength of e.g. seven OFDM symbols (OS). As CC2 is configured 20S-UL TTIrespectively 3OS-UL TTI, the UE will report virtual for CC2, i.e. PHRcalculation is performed for 7OS-UL TTI and there is no 70S-ULallocation/transmission on CC2.

Referring back to FIG. 7 , in some embodiments, the UE 205 reports avirtual power headroom corresponding to a first TTI length (e.g.,slot-length TTI) on CC2 within the PHR MAC CE transmitted in sTTI-1 onCC1, although CC2 is not configured with the first TTI length (e.g.,slot-length TTI), but configured with a second TTI length (e.g., 2/3OFDM/SC-FDMA symbol duration).

To calculate the virtual PHR, the UE 205 assumes a TPC state (e.g., “f”used in the power control formula) corresponding to a third TTI length.In one example, the TPC state may be derived from one or both of the TPCstates corresponding to 1 ms and ⅔ symbol sTTI. For example, the thirdTTI can be: a) fixed/specified to 1 ms TTI, b) fixed/specified to ⅔symbol-sTTI, c) indicated/configured to one of 1 ms TTI or ⅔symbol-sTTI, or d) most recently scheduled TTI length on CC2.

In another embodiment, the UE 205 reports a power headroom for CC2corresponding to a TTI length (e.g., 1 ms-length TTI) different than theTTI length configured for CC2 within the PHR MAC CE transmitted insTTI-1 on CC1. For example, referring again to FIG. 3 , the UE 205 mayreport a virtual power headroom for CC2 within the PHR MAC CEtransmitted in sTTI-1 on CC1, wherein the TTI length that the virtualpower headroom for CC2 is based on is different than the TTI lengthassociated with the sPUSCH transmission on CC2. One example of computinga power headroom for a component carrier/serving cell based on a TTIlength being different than the TTI length configured for this componentcarrier/serving cell is described above with reference to FIG. 3 .

According to one embodiment, the UE 205 aggregating multiple servingcells reports an actual PHR for a serving cell/CC according to aconfigured grant, i.e. UL resources allocated without dynamicscheduling, even though there is no PUSCH transmission in thecorresponding TTI on that serving cell. Here, the UE 205 transmits thePHR MAC CE on one of the other activated serving cells on which a PUSCHtransmission takes place.

For cases when UE 205 has no data available for transmission in itsbuffer, UE 205 may not perform an uplink transmission on PUSCH eventhough it has a valid resource allocation, e.g., allocated by aconfigured grant like SPS scheduling. Because there is no higher layerdata available, the UE 205 would otherwise send a MAC PDU which containsonly padding bits and potentially padding BSR. However, from a powerheadroom reporting perspective, it will be still useful to send anactual PHR for the serving cell, i.e. Power headroom calculation isbased on the uplink resource allocation, even when there is no PUSCHtransmission, since the actual PHR provides more information to the RANnode than a virtual PHR.

The actual PHR provides for example information on the used MPR for thecorresponding uplink allocation, which is not provided by a virtual PHR,i.e. MPR is set to 0 dB for a virtual PHR. Furthermore, the UE 205 mightknow at a late point of time whether it will skip the uplinktransmission or not due to changes in its transmission buffer.

FIG. 10 depicts a sixth scenario 1000 where the UE 205 aggregatesserving cells (e.g., in a carrier aggregation deployment) with differentTTI lengths, according to various embodiments of the disclosure. Here,the UE 205 aggregates a first component carrier (e.g., “CC1”) 1005 andsecond component carrier (e.g., “CC2”) 1010. Note that in the sixthscenario 1000, the UE 205 is scheduled for sPUSCH on sTTI-4 of CC1 andsTTI-13 and sTTI-14 of CC2.

In the sixth scenario 1000, the UE 205 at sTTI-0 on CC1 when receivingan UL grant allocating PUSCH resources in sTTI-4 which contains a PHRMAC CE, i.e. there was a triggered PHR pending before sTTI-0, is notaware of the presence of a UL grant received for the overlappingsTTI-13. However, the UE 205 at sTTI-0 on CC1 is aware of the configuredgrant for sTTI-14 on CC2. Therefore, the UE 205 may report an actual PHRfor CC2 for sTTI-14 within the PHR MAC CE contained in the PUSCH insTTI-4 on CC1.

Because at the point of time when UE is generating the PHR MAC CE it isonly aware of the configured grant in sTTI-14, the UE reports an actualPHR for this sTTI on CC2 even though the UE 205 might later on skip thecorresponding PUSCH transmission on CC2 (in sTTI-14) due to an emptybuffer. It should be noted that the PHR format is different for anactual reported PHR and a virtual PHR due to the fact that the UEreports P_(CMAX,c) for an actual PHR in addition to the PH info.Therefore, in various embodiments the UE 205 follows the determined PHRformat even if, later on, the UE 205 is actually not performing a PUSCHtransmission on a serving cell for which an actual PHR is reported.

According to another embodiment, the UE 205 aggregating several servingcells reports an actual PHR for a serving cell according to a dynamic ULgrant, i.e. UL resource allocated by downlink control information (DCI),even though the UE skips the corresponding PUSCH transmission on thisserving cell since there is no data available for transmission in thebuffer. Similar as for the previous embodiment, reporting an actual PHRis beneficial for the scheduler since the actual PHR, i.e. powerheadroom information calculation computed according to the received ULgrant, provides information on the MPR used for the corresponding ULallocation.

Referring again to FIG. 9 , the UE 205 may transmit a PHR MAC CE insTTI-4 on CC1 including a virtual PH for CC2 because the UE is not awareof any uplink allocations in the “overlapping” sTTIs on CC2 whengenerating the PHR MAC CE. In the case where the UE 205 receives laterin sTT8 on CC2 an UL grant for sTTI-14, the UE 205 may include a PHR MACCE in the corresponding PUSCH transmission in sTTI-14 which includes anactual PHR for CC2 (actual PHR computed based on UL grant for sTTI-14).This second PHR MAC CE provides more detailed information to thescheduler in the RAN node, e.g., because it also provides information onthe used MPR for CC2.

For cases where a “longer” sTTI overlaps with several “shorter” sTTIsand several of these overlapping (s)TTIs are scheduled for an uplinktransmission, a rule (e.g., network policy) allows for unambiguousdetermination of which of the overlapping (s)TTIs UE reports powerheadroom information.

The PHR is used to give the scheduler (in RAN node) an indicationwhether additional resources can be scheduled without power scaling atthe UE 205, or whether resources should be reduced to avoid the powerscaling. Therefore, according to another embodiment, the UE 205 reportsthe smallest PHR across the scheduled “overlapping” sTTIs. Referringagain to FIG. 7 , the UE 205 may report for CC2, the smallest actual PHRof the multiple (scheduled) overlapping sTTIs (e.g., that of sTTI-3 onCC2).

According to another embodiment, the PHR MAC CE includes a field toindicate which TDU was used for the PHR computation for CC2. Then thescheduler in the RAN node unambiguously knows which UL grant is thereference for the PH computation. Including the information explicitlyin the PHR MAC CE would be also a safeguard against the loss of an ULgrant, i.e. a situation where the base station scheduled sTTI-1 throughsTTI-3 on CC2, but the UE 205 only detects the scheduling for sTTI-2 andsTTI-3. In that case, if there is no explicit TDU indicator included inthe PHR MAC CE, but only the rule exists that the PHR is based on thefirst overlapping scheduled sTTI, the UE 205 would report for sTTI-2 onCC2, but the RAN nodes would (incorrectly) interpret it as a PHR validfor sTTI-1 on CC2.

Furthermore, for the case where the UE 205 is free to choose which TDUis the reference for the reported sTTI (i.e. the UE 205 would be free tonot report the minimum PHRs for that carrier), the indication of thereference TDU is used by the scheduler to correctly interpret thereported PH information and to use this information for future uplinkresource allocations.

In one embodiment, on a first CC in which the PHR MAC CE is nottransmitted, if PUSCH is scheduled on this carrier (CC1) in the subframein which the PHR is transmitted on the second CC (CC2), and an sPUSCHalso is scheduled on the first CC or sPUCCH is transmitted on the firstCC, then the PUSCH transmission is stopped or dropped in the subframe onthe first CC and sPUSCH/sPUCCH is transmitted on the first CC. Here, thePHR for this carrier (first CC) is an actual PHR for the scheduledPUSCH.

FIG. 11 depicts one embodiment of a method 1100 for receiving a pagingmessage, according to embodiments of the disclosure. In someembodiments, the method 1100 is performed by a remote unit, such as theremote unit 105, the UE 205, and/or the user equipment apparatus 400. Incertain embodiments, the method 1100 may be performed by a processorexecuting program code, for example, a microcontroller, amicroprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, orthe like.

The method 1100 begins and the remote unit communicates 1105 with a baseunit using a first uplink carrier and a second uplink carrierconcurrently. Here, each carrier has a different transmission durationunit length, wherein the first uplink carrier has a longer transmissionduration unit length than the second uplink carrier. In someembodiments, each of the first and second uplink carriers is associatedwith a different serving cell.

The method 1100 includes receiving 1110 an uplink resource allocationfor a first transmission duration unit on the first uplink carrier.Here, the first transmission duration unit overlaps in time with atleast two second transmission duration units on the second uplinkcarrier.

In certain embodiments, the remote unit also receives an uplink resourceallocation for at least one of the overlapping second transmissionduration units on the second uplink carrier.

The method 1100 includes determining 1115 a third transmission durationunit on the second uplink carrier. Here, the third transmission durationunit comprises at least one of the second transmission duration units.

The method 1100 includes calculating 1120 PH information for the seconduplink carrier associated with the third transmission duration unit andreporting 1125 the PH information in an uplink transmission on the firsttransmission duration unit. The method 1100 ends. In some embodiments,the PH information is calculated according to a predefined referenceformat. In certain embodiments, the PH information is calculatedassuming the apparatus is not scheduled to transmit a PUSCH in the thirdtransmission duration unit.

In some embodiments, the first transmission duration unit corresponds toa slot on the first uplink carrier and the second transmission durationunit corresponds to a slot on the second uplink carrier. In certainembodiments, multiple second slots on the second uplink carrier fullyoverlap with the first slot. In such embodiments, calculating 1120 PHinformation may include calculating PH information for a first physicaluplink shared channel (“PUSCH”) scheduled on the first of the multiplesecond slots that fully overlaps with the first slot on the first uplinkcarrier, wherein reporting 1125 the PH information for the second uplinkcarrier in an uplink transmission on the first slot comprisestransmitting on a PUSCH a power headroom report (“PHR”) that containsthe PH information for the first PUSCH. In certain embodiments, thefirst uplink carrier is configured with a first subcarrier spacing(“SCS”) and the second uplink carrier is configured with a second SCS,wherein the first SCS is smaller than the second SCS.

In some embodiments, the first transmission duration unit corresponds toa transmit time interval (“TTI”) of the first uplink carrier and thesecond transmission duration unit corresponds to a TTI of the seconduplink carrier. In certain embodiments, the first uplink carrier isconfigured with a first TTI length and the second uplink carrier isconfigured with a second TTI length, wherein the first TTI length islarger than the second TTI length. In such embodiments, calculating 1120PH information for the second uplink carrier associated with the thirdtransmission duration unit comprises calculating PH for a TTI durationlonger than the second TTI length.

In certain embodiments, the length of the third transmission durationunit is greater than the length of the first TTI. In certainembodiments, the third transmission duration unit is equal to asubframe. In certain embodiments, calculating 1120 PH information forthe second uplink carrier associated with the third transmissionduration unit comprises calculating PH information for a subframecontaining the first TTI. In certain embodiments, the third transmissionduration unit contains multiple TTIs of the second uplink carrier.

In various embodiments, the reporting 1125 PH information comprisesreporting a power headroom level computed based on the uplink resourceallocation. In some embodiments, the at least one of the secondtransmission duration units on the second uplink carrier (e.g., secondTTI on the second uplink carrier) has a shortened TTI length that isless than 1 millisecond. In some embodiments, the PH information iscalculated based on an uplink resource allocation received for the thirdtransmission duration unit. In such embodiments, the uplink transmissionon the third transmission duration may be either stopped or dropped.

FIG. 12 depicts one embodiment of a method 1200 for reporting powerheadroom information, according to embodiments of the disclosure. Invarious embodiments, the method 1200 is performed by a UE device, suchas the remote unit 105, the UE 205, and/or the user equipment apparatus400. In some embodiments, the method 1200 is performed by a processor,such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliaryprocessing unit, a FPGA, or the like.

The method 1200 begins and receives 1205 a configuration for a firstserving cell for physical uplink shared channel (“PUSCH”) transmissionshaving a first subcarrier spacing (“SCS”) and a second serving cell forPUSCH transmissions having a second SCS, wherein the first SCS issmaller than the second SCS. The method 1200 includes receiving 1210 anuplink resource allocation for a first slot on the first serving cell,wherein the first slot overlaps in time with multiple second slots onthe second serving cell. The method 1200 includes receiving 1215 anuplink resource allocation for at least one of the multiple second slotson the second serving cell that are overlapped by the first slot on thefirst serving cell. The method 1200 includes calculating 1220 powerheadroom (“PH”) information for the second serving cell for a firstPUSCH scheduled on a first slot of the multiple second slots that fullyoverlaps with the first slot on the first serving cell. The method 1200includes transmitting 1225 the PH information in an uplink transmissionon the first slot on the first serving cell. The method 1200 ends.

Disclosed herein is a first apparatus for reporting power headroominformation, according to embodiments of the disclosure. The firstapparatus may be implemented by a UE device, such as the remote unit105, the UE 205, and/or the user equipment apparatus 400, describedabove. The first apparatus includes a transceiver and a processor. Thefirst apparatus is configured with (i.e., the processor receives aconfiguration via the transceiver for) a first serving cell for PUSCHtransmissions having a first SCS and a second serving cell for PUSCHtransmissions having a second SCS, where the first SCS is smaller thanthe second SCS. The first apparatus has (i.e., the processor receivesvia the transceiver) an uplink resource allocation for a first slot onthe first serving cell, where the first slot overlaps in time withmultiple second slots on the second serving cell. Additionally, thefirst apparatus has (i.e., the processor receives via the transceiver)an uplink resource allocation for at least one of the multiple secondslots on the second serving cell that are overlapped by the first sloton the first serving cell. The processor calculates power headroom(“PH”) information for the second serving cell for a first PUSCHscheduled on a first slot of the multiple second slots that fullyoverlaps with the first slot on the first serving cell and controls thetransceiver to transmit the PH information in an uplink transmission onthe first slot on the first serving cell.

In some embodiments, the processor further receives (via thetransceiver) a second uplink resource allocation for at least one of theoverlapping second slots on the second uplink carrier. In someembodiments, transmitting the PH information in an uplink transmissionon the first slot on the first serving cell includes transmitting on aPUSCH a PHR that contains the PH information for the first PUSCHscheduled on the first of the multiple second slots that is fullyoverlapped by the first slot.

In some embodiments, transmitting the PH information includestransmitting a Type 1 power headroom report. In some embodiments,transmitting the PH information includes transmitting a PHR MAC CE inthe uplink transmission in an allocated uplink allocation on the firstserving cell.

In some embodiments, the first slot corresponds to a TTI of the firstserving cell and the second slots correspond to TTIs of the secondserving cell. In certain embodiments, the PH information for the secondserving cell is calculated for TTI duration that contains multiple TTIsof the second serving cell.

In some embodiments, the first serving cell is configured with a firstTTI length and the second serving cell is configured with a second TTIlength, where the first TTI length is larger than the second TTI length.In certain embodiments, calculating PH information for the secondserving cell includes calculating PH information for a subframe thatuses the first TTI length.

In certain embodiments, calculating PH information for the secondserving cell includes calculating PH for a TTI duration longer than thesecond TTI length. In one embodiment, the PH for the second serving cellis calculated for TTI duration that is greater than the length of thefirst TTI. In another embodiment, the PH for the second serving cell iscalculated for TTI duration that is equal to a subframe.

In some embodiments, the PH information is calculated according to apredefined reference format. In certain embodiments, the PH informationis calculated assuming the UE is not scheduled to transmit a PUSCH inthe at least two second slots that fully overlaps with the first slot.

In some embodiments, the at least one of the second slots on the secondserving cell has a shortened TTI length that is less than 1 millisecond.In some embodiments, the reported PH information includes a powerheadroom level computed based on the uplink resource allocation.

In some embodiments, the PH information is calculated based on an uplinkresource allocation received for a transmission duration correspondingto multiple second slots on the second serving cell that are overlappedby the first slot on the first serving cell. In certain embodiments, anuplink transmission on the transmission duration is one of: stopped anddropped.

Disclosed herein is a first method for reporting power headroominformation, according to embodiments of the disclosure. The firstmethod may be performed by a UE device, such as the remote unit 105, theUE 205, and/or the user equipment apparatus 400, described above. Thefirst method includes being configured with a first serving cell forPUSCH transmissions having a first SCS and a second serving cell forPUSCH transmissions having a second SCS, where the first SCS is smallerthan the second SCS. The first method includes having an uplink resourceallocation for a first slot on the first serving cell, where the firstslot overlaps in time with multiple second slots on the second servingcell, and having an uplink resource allocation for at least one of themultiple second slots on the second serving cell that are overlapped bythe first slot on the first serving cell. The first method includescalculating power headroom (“PH”) information for the second servingcell for a first PUSCH scheduled on a first slot of the multiple secondslots that fully overlaps with the first slot on the first serving cell.The first method includes transmitting the PH information in an uplinktransmission on the first slot on the first serving cell.

In some embodiments, the first method further includes receiving asecond uplink resource allocation for at least one of the overlappingsecond slots on the second uplink carrier. In some embodiments,transmitting the PH information in an uplink transmission on the firstslot on the first serving cell includes transmitting on a PUSCH a MRthat contains the PH information for the first PUSCH scheduled on thefirst of the multiple second slots that is fully overlapped by the firstslot.

In some embodiments, transmitting the PH information includestransmitting a Type 1 power headroom report. In some embodiments,transmitting the PH information includes transmitting a PHR MAC CE inthe uplink transmission in an allocated uplink allocation on the firstserving cell.

In some embodiments, the first slot corresponds to a TTI of the firstserving cell and the second slots correspond to TTIs of the secondserving cell. In certain embodiments, the PH information for the secondserving cell is calculated for TTI duration that contains multiple TTIsof the second serving cell.

In some embodiments, the first serving cell is configured with a firstTTI length and the second serving cell is configured with a second TTIlength, where the first TTI length is larger than the second TTI length.In certain embodiments, calculating PH information for the secondserving cell includes calculating PH information for a subframe thatuses the first TTI length.

In certain embodiments, calculating PH information for the secondserving cell includes calculating PH for a TTI duration longer than thesecond TTI length. In one embodiment, the PH for the second serving cellis calculated for TTI duration that is greater than the length of thefirst TTI. In another embodiment, the PH for the second serving cell iscalculated for TTI duration that is equal to a subframe.

In some embodiments, the PH information is calculated according to apredefined reference format. In certain embodiments, the PH informationis calculated assuming the UE is not scheduled to transmit a PUSCH inthe at least two second slots that fully overlaps with the first slot.

In some embodiments, the at least one of the second slots on the secondserving cell has a shortened TTI length that is less than 1 millisecond.In some embodiments, the reported PH information includes a powerheadroom level computed based on the uplink resource allocation.

In some embodiments, the PH information is calculated based on an uplinkresource allocation received for a transmission duration correspondingto the multiple second slots on the second serving cell that areoverlapped by the first slot on the first serving cell. In certainembodiments, an uplink transmission on the transmission duration is oneof: stopped and dropped.

Disclosed herein is a second apparatus for reporting power headroom(“PH”) information. In various embodiments, the second apparatus may bethe remote unit 105, the UE 205, and/or the user equipment apparatus400. The second apparatus includes a transceiver that communicates witha base unit using a first uplink carrier and a second uplink carrierconcurrently. Here, each carrier has a different transmission durationunit length, wherein the first uplink carrier has a longer transmissionduration unit length than the second uplink carrier. The secondapparatus also includes a processor that receives an uplink resourceallocation for a first transmission duration unit on the first uplinkcarrier. Here, the first transmission duration unit overlaps in timewith at least two second transmission duration units on the seconduplink carrier. The processor also determines a third transmissionduration unit on the second uplink carrier. Here, the third transmissionduration unit comprises at least one of the second transmission durationunits. The processor calculates PH information for the second uplinkcarrier associated with the third transmission duration unit andreports, via the transceiver, the PH information in an uplinktransmission on the first transmission duration unit.

In some embodiments, each of the first and second uplink carriers isassociated with a different serving cell. In some embodiments, theprocessor further receives an uplink resource allocation for at leastone of the overlapping second transmission duration units on the seconduplink carrier.

In some embodiments, the first transmission duration unit corresponds toa slot on the first uplink carrier and the second transmission durationunit corresponds to a slot on the second uplink carrier. In certainembodiments, multiple second slots on the second uplink carrier fullyoverlap with the first slot. In such embodiments, the processorcalculates PH information for a first physical uplink shared channel(“PUSCH”) scheduled on the first of the multiple second slots that fullyoverlaps with the first slot on the first uplink carrier, whereinreporting PH information for the second uplink carrier in an uplinktransmission on the first slot comprises transmitting on a PUSCH a powerheadroom report (“PHR”) that contains the PH information for the firstPUSCH. In certain embodiments, the first uplink carrier is configuredwith a first subcarrier spacing (“SCS”) and the second uplink carrier isconfigured with a second SCS, wherein the first SCS is smaller than thesecond SCS.

In some embodiments, the first transmission duration unit corresponds toa transmit time interval (“TTI”) of the first uplink carrier and thesecond transmission duration unit corresponds to a TTI of the seconduplink carrier. In certain embodiments, the first uplink carrier isconfigured with a first TTI length and the second uplink carrier isconfigured with a second TTI length, wherein the first TTI length islarger than the second TTI length. In such embodiments, calculating PHinformation for the second uplink carrier associated with the thirdtransmission duration unit comprises calculating PH for a TTI durationlonger than the second TTI length.

In certain embodiments, the length of the third transmission durationunit is greater than the length of the first TTI. In certainembodiments, the third transmission duration unit is equal to asubframe. In certain embodiments, calculating PH information for thesecond uplink carrier associated with the third transmission durationunit comprises calculating PH information for a subframe containing thefirst TTI. In certain embodiments, the third transmission duration unitcontains multiple TTIs of the second uplink carrier.

In some embodiments, the processor calculates the PH informationaccording to a predefined reference format. In certain embodiments, theprocessor calculates the PH information assuming the apparatus is notscheduled to transmit a PUSCH in the third transmission duration unit.

In various embodiments, the reported PH information comprises a powerheadroom level computed based on the uplink resource allocation. In someembodiments, the at least one of the second transmission duration unitson the second uplink carrier has a shortened TTI length that is lessthan 1 millisecond. In some embodiments, the PH information iscalculated based on an uplink resource allocation received for the thirdtransmission duration unit. In such embodiments, the uplink transmissionon the third transmission duration may be either stopped or dropped.

Disclosed herein is a second method for reporting power headroom (“PH”)information. In various embodiments, the second method is performed by aUE, such as the remote unit 105, the UE 205, and/or the user equipmentapparatus 400. The second method includes the UE communicating with abase unit using a first uplink carrier and a second uplink carrierconcurrently. Here, each carrier has a different transmission durationunit length, wherein the first uplink carrier has a longer transmissionduration unit length than the second uplink carrier. The second methodincludes receiving an uplink resource allocation for a firsttransmission duration unit on the first uplink carrier. Here, the firsttransmission duration unit overlaps in time with at least two secondtransmission duration units on the second uplink carrier. The secondmethod includes determining a third transmission duration unit on thesecond uplink carrier. Here, the third transmission duration unitcomprises at least one of the second transmission duration units. Thesecond method includes calculating PH information for the second uplinkcarrier associated with the third transmission duration unit andreporting the PH information in an uplink transmission on the firsttransmission duration unit.

In some embodiments, each of the first and second uplink carriers isassociated with a different serving cell. In some embodiments, thesecond method further includes receiving an uplink resource allocationfor at least one of the overlapping second transmission duration unitson the second uplink carrier.

In some embodiments, the first transmission duration unit corresponds toa slot on the first uplink carrier and the second transmission durationunit corresponds to a slot on the second uplink carrier. In certainembodiments, multiple second slots on the second uplink carrier fullyoverlap with the first slot. In such embodiments, the method furtherincludes calculating PH information for a first physical uplink sharedchannel (“PUSCH”) scheduled on the first of the multiple second slotsthat fully overlaps with the first slot on the first uplink carrier,wherein reporting PH information for the second uplink carrier in anuplink transmission on the first slot comprises transmitting on a PUSCHa power headroom report (“PHR”) that contains the PH information for thefirst PUSCH. In certain embodiments, the first uplink carrier isconfigured with a first subcarrier spacing (“SCS”) and the second uplinkcarrier is configured with a second SCS, wherein the first SCS issmaller than the second SCS.

In some embodiments, the first transmission duration unit corresponds toa transmit time interval (“TTI”) of the first uplink carrier and thesecond transmission duration unit corresponds to a TTI of the seconduplink carrier. In certain embodiments, the first uplink carrier isconfigured with a first TTI length and the second uplink carrier isconfigured with a second TTI length, wherein the first TTI length islarger than the second TTI length. In such embodiments, calculating PHinformation for the second uplink carrier associated with the thirdtransmission duration unit comprises calculating PH for a TTI durationlonger than the second TTI length.

In certain embodiments, the length of the third transmission durationunit is greater than the length of the first TTI. In certainembodiments, the third transmission duration unit is equal to asubframe. In certain embodiments, calculating PH information for thesecond uplink carrier associated with the third transmission durationunit comprises calculating PH information for a subframe containing thefirst TTI. In certain embodiments, the third transmission duration unitcontains multiple TTIs of the second uplink carrier.

In some embodiments, the PH information is calculated according to apredefined reference format. In certain embodiments, the PH informationis calculated assuming the apparatus is not scheduled to transmit aPUSCH in the third transmission duration unit.

In various embodiments, the reported PH information comprises a powerheadroom level computed based on the uplink resource allocation. In someembodiments, the at least one of the second transmission duration unitson the second uplink carrier has a shortened TTI length that is lessthan 1 millisecond. In some embodiments, the PH information iscalculated based on an uplink resource allocation received for the thirdtransmission duration unit. In such embodiments, the uplink transmissionon the third transmission duration may be either stopped or dropped.

Embodiments may be practiced in other specific forms. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed is:
 1. A method of a User Equipment (“UE”) device, themethod comprising: being configured with a first serving cell forphysical uplink shared channel (“PUSCH”) transmissions having a firstsubcarrier spacing (“SCS”) and a second serving cell for PUSCHtransmissions having a second SCS, wherein the first SCS is smaller thanthe second SCS; having an uplink resource allocation for a first slot onthe first serving cell, wherein the first slot overlaps in time withmultiple second slots on the second serving cell; having an uplinkresource allocation for at least one of the multiple second slots on thesecond serving cell that are overlapped by the first slot on the firstserving cell; calculating power headroom (“PH”) information for thesecond serving cell for a first PUSCH scheduled on a first slot of themultiple second slots that fully overlaps with the first slot on thefirst serving cell; and transmitting the PH information in an uplinktransmission on the first slot on the first serving cell.
 2. The methodof claim 1, further comprising receiving a second uplink resourceallocation for at least one of the overlapping second slots on thesecond uplink carrier.
 3. The method of claim 1, wherein transmittingthe PH information in an uplink transmission on the first slot on thefirst serving cell comprises transmitting on a PUSCH a power headroomreport (“PHR”) that contains the PH information for the first PUSCHscheduled on the first of the multiple second slots that is fullyoverlapped by the first slot.
 4. The method of claim 1, whereintransmitting the PH information comprises transmitting a Type 1 powerheadroom report.
 5. The method of claim 1, wherein transmitting the PHinformation comprises transmitting a power headroom report (“PHR”)medium access control (“MAC”) control element (“CE”) in the uplinktransmission in an allocated uplink allocation on the first servingcell.
 6. The method of claim 1, wherein the first slot corresponds to atransmit time interval (“TTI”) of the first serving cell and the secondslots correspond to TTIs of the second serving cell.
 7. The method ofclaim 6, wherein the first serving cell is configured with a first TTIlength and the second serving cell is configured with a second TTIlength, wherein the first TTI length is larger than the second TTIlength.
 8. The method of claim 7, wherein calculating PH information forthe second serving cell comprises calculating PH for a TTI durationlonger than the second TTI length.
 9. The method of claim 8, wherein thePH for the second serving cell is calculated for TTI duration that isgreater than the length of the first TTI.
 10. The method of claim 8,wherein the PH for the second serving cell is calculated for TTIduration that is equal to a subframe.
 11. The method of claim 7, whereincalculating PH information for the second serving cell comprisescalculating PH information for a subframe that uses the first TTIlength.
 12. The method of claim 6, wherein the PH information for thesecond serving cell is calculated for TTI duration that containsmultiple TTIs of the second serving cell.
 13. The method of claim 1,wherein the PH information is calculated according to a predefinedreference format.
 14. The method of claim 13, wherein the PH informationis calculated assuming the UE is not scheduled to transmit a PUSCH inthe at least two second slots that fully overlaps with the first slot.15. The method of claim 1, wherein the at least one of the second slotson the second serving cell has a shortened TTI length that is less than1 millisecond.
 16. The method of claim 1, wherein the reported PHinformation comprises a power headroom level computed based on theuplink resource allocation.
 17. The method of claim 1, wherein the PHinformation is calculated based on an uplink resource allocationreceived for a transmission duration corresponding to the multiplesecond slots on the second serving cell that are overlapped by the firstslot on the first serving cell.
 18. The method of claim 17, wherein anuplink transmission on the transmission duration is one of: stopped anddropped.
 19. An apparatus comprising: a processor that: is configuredwith a first serving cell for physical uplink shared channel (“PUSCH”)transmissions having a first subcarrier spacing (“SCS”) and a secondserving cell for PUSCH transmissions having a second SCS, wherein thefirst SCS is smaller than the second SCS; has an uplink resourceallocation for a first slot on the first serving cell, wherein the firstslot overlaps in time with multiple second slots on the second servingcell; has an uplink resource allocation for at least one of the multiplesecond slots on the second serving cell that are overlapped by the firstslot on the first serving cell; and calculates power headroom (“PH”)information for the second serving cell for a first PUSCH scheduled on afirst slot of the multiple second slots that fully overlaps with thefirst slot on the first serving cell; and a transceiver that transmitsthe PH information in an uplink transmission on the first slot on thefirst serving cell.
 20. The apparatus of claim 19, wherein transmittingPH information in an uplink transmission on the first slot on the firstserving cell comprises transmitting on a PUSCH a power headroom report(“PHR”) that contains the PH information for the first PUSCH scheduledon the first of the multiple second slots that is fully overlapped bythe first slot.